海水淡化过程需要消耗大量的能源。采用较低热源温度驱动的海水淡化技术将是未来的发展方向。针对热力压缩海水淡化系统,设计了可在低温热源驱动下工作的蒸汽喷射器。通过实验分别研究了蒸汽喷射器的工况参数、横截面的面积比和喷嘴类...海水淡化过程需要消耗大量的能源。采用较低热源温度驱动的海水淡化技术将是未来的发展方向。针对热力压缩海水淡化系统,设计了可在低温热源驱动下工作的蒸汽喷射器。通过实验分别研究了蒸汽喷射器的工况参数、横截面的面积比和喷嘴类型等对蒸汽喷射器性能的影响。结果表明:当发生温度为40℃、蒸发温度为25℃时,蒸汽喷射器的性能系数(cofficient of performance,COP)可达到3.06;面积比对蒸汽喷射器的COP有较大的影响,而对临界冷凝温度的影响不大;渐缩型喷嘴的性能略优于渐缩渐扩型喷嘴的性能。研究为今后进一步开展低温热源驱动海水淡化技术奠定了基础。展开更多
建立氨水液-汽型喷射器的一维稳态热力学模型,对喷射器的热力学性能与结构进行研究,包括工作喷嘴、扩散段中的工作流体与引射流体的压力及速度的变化,以及不同扩散角对喷射器性能的影响。将氨水液-汽型喷射器应用于Kalina循环,以降低膨...建立氨水液-汽型喷射器的一维稳态热力学模型,对喷射器的热力学性能与结构进行研究,包括工作喷嘴、扩散段中的工作流体与引射流体的压力及速度的变化,以及不同扩散角对喷射器性能的影响。将氨水液-汽型喷射器应用于Kalina循环,以降低膨胀机的背压来提高循环输出功与效率。在对喷射器性能,如:引射系数、引射压力及混合出口压力等相互关系分析基础上,以得到Kalina循环更高的循环输出功为目的,对喷射器的性能与结构进行研究。结果表明,喷射器的扩散角越小,越有利于喷射器的压力回收,扩散角越大,越有利于汽、液两相的混合。给定喷射器混合出口压力时,引射系数越小,引射压力越小。引射系数对提高Kalina循环性能起关键作用。最终优化得到的喷射器设计工况为:扩散角为1°、引射系数0.1、引射压力656 k Pa。展开更多
The vapor-liquid ejector is a simply flow device and driven by thermal energy. In this paper, a modified mathematical model of the vapor-liquid ejector is proposed, and the validation shows good agreements with the ex...The vapor-liquid ejector is a simply flow device and driven by thermal energy. In this paper, a modified mathematical model of the vapor-liquid ejector is proposed, and the validation shows good agreements with the experimental data. A study is carried out with six organic working fluids, namely R1233 zd(E), R1336 mzz(Z), R236 ea, R245 ca, R245 fa and R365 mfc. The influences of the entrainment ratio, the area ratio, the superheating at the vapor nozzle inlet, the subcooling at the liquid nozzle inlet, and the pressures at these inlets on the pressure lifting are parametrically investigated. An increase in the subcooling leads to the great increasing of pressure lifting and the superheating has slight effect on the pressure lifting, whereas others have the opposite tendency. The studies of the pressures and temperatures at the typical locations inside the vapor-liquid ejector are further conducted by using R1336 mzz(Z). The results show that the above parameters have great influence on these pressures and temperatures inside except that the pressures are insignificantly impacted by the superheating, and the temperatures are negligibly affected by the area ratio. R1336 mzz(Z) is recommended as a good working fluid for the vapor-liquid ejector.展开更多
文摘海水淡化过程需要消耗大量的能源。采用较低热源温度驱动的海水淡化技术将是未来的发展方向。针对热力压缩海水淡化系统,设计了可在低温热源驱动下工作的蒸汽喷射器。通过实验分别研究了蒸汽喷射器的工况参数、横截面的面积比和喷嘴类型等对蒸汽喷射器性能的影响。结果表明:当发生温度为40℃、蒸发温度为25℃时,蒸汽喷射器的性能系数(cofficient of performance,COP)可达到3.06;面积比对蒸汽喷射器的COP有较大的影响,而对临界冷凝温度的影响不大;渐缩型喷嘴的性能略优于渐缩渐扩型喷嘴的性能。研究为今后进一步开展低温热源驱动海水淡化技术奠定了基础。
文摘建立氨水液-汽型喷射器的一维稳态热力学模型,对喷射器的热力学性能与结构进行研究,包括工作喷嘴、扩散段中的工作流体与引射流体的压力及速度的变化,以及不同扩散角对喷射器性能的影响。将氨水液-汽型喷射器应用于Kalina循环,以降低膨胀机的背压来提高循环输出功与效率。在对喷射器性能,如:引射系数、引射压力及混合出口压力等相互关系分析基础上,以得到Kalina循环更高的循环输出功为目的,对喷射器的性能与结构进行研究。结果表明,喷射器的扩散角越小,越有利于喷射器的压力回收,扩散角越大,越有利于汽、液两相的混合。给定喷射器混合出口压力时,引射系数越小,引射压力越小。引射系数对提高Kalina循环性能起关键作用。最终优化得到的喷射器设计工况为:扩散角为1°、引射系数0.1、引射压力656 k Pa。
基金supported by the National Natural Science Foundation of China(51706047)Guangdong Special Funding for Applied Technology R&D(2016B020243010)Foshan Science&Technology Innovation Project(2016AG101232)
文摘The vapor-liquid ejector is a simply flow device and driven by thermal energy. In this paper, a modified mathematical model of the vapor-liquid ejector is proposed, and the validation shows good agreements with the experimental data. A study is carried out with six organic working fluids, namely R1233 zd(E), R1336 mzz(Z), R236 ea, R245 ca, R245 fa and R365 mfc. The influences of the entrainment ratio, the area ratio, the superheating at the vapor nozzle inlet, the subcooling at the liquid nozzle inlet, and the pressures at these inlets on the pressure lifting are parametrically investigated. An increase in the subcooling leads to the great increasing of pressure lifting and the superheating has slight effect on the pressure lifting, whereas others have the opposite tendency. The studies of the pressures and temperatures at the typical locations inside the vapor-liquid ejector are further conducted by using R1336 mzz(Z). The results show that the above parameters have great influence on these pressures and temperatures inside except that the pressures are insignificantly impacted by the superheating, and the temperatures are negligibly affected by the area ratio. R1336 mzz(Z) is recommended as a good working fluid for the vapor-liquid ejector.
